1. Field of the Invention
This invention relates generally to refrigerated display cases and, more particularly, to a method and apparatus for cooling in a refrigerated display case.
2. Description of the Related Art
In contemporary supermarket display cases which are open-faced, a cold air curtain or air flow is provided over the open-face in order to contain the cold air inside the case, and to protect the front merchandise from exposure to warm ambient air. A significant amount of mixing occurs along the air curtain as it flows downward over the open-face of the display case, resulting in infiltration of warm store air into the case and the displacement of an equal amount of cold air out of the case and into the store aisles. This results in a fairly inefficient operation of the store refrigeration system, as well as uncomfortable store aisle conditions for shoppers.
Other contemporary devices have attempted to reduce the mixing along the cold air curtain. However, such efforts have still allowed a significant amount of mixing to occur at the air curtain interface, resulting in a large amount of cold air leaving the display cases and decreasing the efficiency of the vapor-compression refrigeration system that is used to generate the cold air curtain.
Accordingly, there is a need for a refrigeration display case that improves the efficiency of the operation of the display case. There is a further need for reducing the amount of cold air that leaves the display case. The method and apparatus of the present invention recovers some of the lost energy through the use of a thermoelectric heat pump or cooler.
It is an object of the present invention to provide a thermoelectric heat pump for a refrigerant display case that reduces capacity and energy consumption of the store vapor-compression system.
It is a further object of the present invention to provide such a thermoelectric heat pump that reduces capital cost for the vapor-compression mechanical equipment.
It is yet a further object of the present invention to provide a configuration that allows for more optimal operation of the thermoelectric heat pump at a lower temperature differential (DT) using cold spill air.
It is another further object of the present invention to provide such a thermoelectric heat pump for a refrigerant display case that improves store aisle conditions for shoppers.
It is yet another object of the present invention to provide such a thermoelectric heat pump for a refrigerant display case that reduces the potential for condensation at the base of the display cases.
It is yet another further object of the present invention to provide such a thermoelectric heat pump for a refrigerant display case that lowers the evaporator load and defrost requirements.